The present invention relates to a sheet post treatment apparatus, and more particularly to a sheet post treatment apparatus applied to a stapler sorter attached to the sheet discharge part of an office machinery, like a copying machine or facsimile, and comprising multiple bin trays, which through ascending or descending operations at regular intervals, successively separate and carry sheets discharged from said sheet discharge part by or in the order of pages and moving and aligning sheets received in said bin tray for stapling within certain limits.
Recently, various convenient functions are provided by office machinery due to the influence of the automation of the office work environment. A sorter needs a stapling function after sorting and several sheet post treatment apparatuses have been proposed to move and align sheets received in bin trays to a site available for stapling.
A traditional sheet post treatment apparatus like the one proposed in the U.S. Pat. No. 5,090,673 is briefly explained in the following, using FIGS. 1 and 2.
FIG. 1 is a perspective view which roughly shows one embodiment of a traditional sheet post treatment apparatus and FIG. 2 is a top plan view which shows the operation of the traditional sheet post treatment apparatus.
In FIGS. 1 and 2, the numbered parts are the following: 101 a bin unit housing, 101a a vertical frame, 101b a lower frame, 102 a bin cover, 103 a bin slot, 104 a bin roller, 105 a bin tray, 106 a slot, 107 an upper arm, 108 a lower arm, 109 a rotation center shaft, 110 a sector gear, 111 an aligning rod, 112 an aligning rod driving motor, 113 an output gear, 114 an alignment reference plate, and 115 a stapler.
As shown in FIGS. 1 and 2, when a sheet discharge part discharges sheets, a sheet post treatment apparatus applied to a stapler sorter moves and aligns the sheets to a site available for stapling.
To said sheet discharge part are attached the bin unit housing 101 consisting of the vertical frame 101a and the lower frame 101b and the designated bin cover 102 where two side ends are supported by vertical frames 101a.
The bin tray 105 is equipped with two bin rollers 104 which moves up and down along bin slots 103 formed in rear vertical frames 101a' of said bin unit housing 101 and the fan-shaped slot 106 of designated size is formed in a designated site of said bin tray 105. To one side of the bin cover 102 and the lower frame 101b are attached two ends of the rotation center shaft 109 which forms one unit with the upper arm 107 and the lower arm 108, and the circular arc-shaped sector gear 110 is equipped in the lower end of the lower arm 108 of said movement center shaft 109. The aligning rod 111 is connected to the upper arm 107 and the lower arm 108 of said rotation center shaft 109 and equipped to be inserted in the slot 106 of said bin tray 105. The aligning rod 111 is rotated to move and align sheets discharged from the sheet discharge part to one side of the bin tray 105 for stapling by the stapler 115.
The aligning driving motor 112 is equipped in the designated lower end part of said bin unit housing 101 and impressed and driven by an external power supply. The output gear 113, equipped in the shaft of the aligning rod driving motor 112, transmits driving power engaged with a sector gear 110.
The alignment reference plate 114, in FIG. 2, is equipped at one side of bin tray 105 and helps in the alignment of one side of the sheets moved to the stapling site of said stapler 115.
The forementioned traditional sheet post treatment apparatus moves and aligns sheets discharged from the sheet discharge part and received in a bin tray at the stapling site of the stapler by the aligning rod 111 rotated by the driving power of the aligning rod driving motor 112.
The forementioned traditional sheet post treatment apparatus requires additional space for the aligning rod hanged up on from the upper end to the lower end of multiple bin trays and thus results in a problem of having big machinery size to that extent. In particular, small size machinery having sheet sizes of two varieties or less have less efficiency regarding increased costs and additional space and a problem in that it is impossible to align sheets having sizes beyond the coverage of the rotation capacity of the aligning rod.
To overcome the aforementioned problems, according to U.S. Pat. No. 5,054,766 as shown in FIG. 3, a sheet post treatment apparatus moving aligning rod by belt was proposed. The straight line-shaped slot 207 of a designated size is formed at one side of said bin tray 201 and the aligning rod 203 is moved through said slot 207. Said aligning rod 203 is fixed at designated sites of belts 205 connected to pulleys 204 equipped at the upper and lower ends of said bin tray 201 and moved to align discharged sheets. This structure allows the aligning of discharged sheets of small sizes but it needs to have additional equipment to move said aligning rod 203, thus resulting in a complex structure of the sorter and increased manufacturing costs.
The forementioned sheet post treatment apparatus has aligning rods through bin trays piled on one another from the upper part to the lower part and thus has on increased driving load and it needs additional space for the aligning rods, resulting in a complex and bigger structure of a sorter.